​ CERTAIN INFORMATION IN THIS DOCUMENT HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

Reversion Products. The following provisions will apply on a Reversion Product-by-Reversion Product basis:

Term. This Agreement will become effective on the Effective Date and, unless earlier terminated pursuant to this [Article 16], will expire # on a Product-by-Product and country-by-country basis, # in the Shared Territory, on the date on which neither Party is Researching, Developing or Commercializing such Product (or any Research Candidate or Development Candidate therefor), and # in the Licensed Territory, at the end of the applicable Royalty Term for such Product, and # on a Reversion Product-by-Reversion Product and country-by-country basis, until such time as no further payments are owed by the Continuing Party to the Opt-Out Party for such Reversion Product in such country (the last such period, the “Term”).

Reversion. Upon receipt of notice of Abandonment by HLTT and at any time during the sixty (60) days following receipt of such notice, PTG may give HLTT written notice that it will make a good faith effort to assist HWC in achieving financial success, which notice shall be accompanied by a budget for the effort and an identification of sources of financing. Upon HLTT’s receipt of that notice with the requisite information, a “Reversion” shall be implemented. HLTT shall transfer to PTG managerial control of HWC, and PTG shall implement its commitment to a good faith effort. If within three years after commencement of

Reversion. At no time, prior to the satisfaction of all liabilities with respect to Participants and their beneficiaries, shall any part of the assets of the Plan be used for or diverted to purposes other than for the exclusive benefit of such persons; provided, however, Employer contributions may be returned to the Employer # if made by the Employer by a mistake of fact, within one year after the payment of the contribution, or # if a contribution is conditioned upon the deductibility of such contribution under Code Section 404, then to the extent the deduction is disallowed, within one year of the disallowance of the deduction. The amount of any contribution that may be returned to the Employer must be reduced by any portion thereof previously distributed from the Trust Fund and by any losses of the Trust Fund allocable thereto, and in no event may the return of such contribution cause any Participant’s Account balances to be less than the amount of such balances had the contribution not been made under the Plan.

Reversion. Upon receipt of notice of Abandonment by HLTT and at any time during the sixty (60) days following receipt of such notice, PTG may give HLTT written notice that it will make a good faith effort to assist HWC in achieving financial success, which notice shall be accompanied by a budget for the effort and an identification of sources of financing. Upon HLTT’s receipt of that notice with the requisite information, a “Reversion” shall be implemented. HLTT shall transfer to PTG managerial control of HWC, and PTG shall implement its commitment to a good faith effort. If within three years after commencement of the Reversion, HWC achieves Cash Flow Positive, as defined above, then HLTT will assign t PTG that number of shares of HWC common stock as will cause the ratio of common stock owned by PTG (excluding common stock issued on conversion of Series A Preferred Stock) to common stock owned by HLTT to equal the ratio of PTG’s capital contributions to HWC to HLTT’s capital contributions to HWC.

Payment Obligations for Reversion Products. On a Reversion Product-by-Reversion Product basis, the Continuing Party will compensate the Opt-Out Party for such Reversion Product as determined in accordance with [Section 3.1(d) or 3.2(c)])], as applicable.

If the Parties agree on such payment obligations for such Reversion Product during such ​ negotiation period, then the Parties will memorialize such payment obligations for such Reversion Product in a definitive agreement.

Joint Development Committee. In accordance with [Section 6.6(c)], the JDC will act as an information-sharing forum with respect to the Research and Development of each Reversion Product. The Continuing Party will provide such information and data regarding the Development of the Reversion Product as the JDC would customarily receive regarding a Product to the extent that it specifically relates to, if Unum is the Opt-Out Party, ACTR T-cells or the ACTR platform technology and, if SGI is the Opt-Out Party, the applicable SGI Antibody. In addition, the Continuing Party will provide summaries of all other material information and data regarding the Development of such Reversion Product. The Parties acknowledge and agree that the Joint Development Committee will have no decision-making authority or approval rights with respect to a Reversion Product.

Transition Assistance. The Transition Agreement will require the Opt-Out Party to, at no cost to the Continuing Party, provide reasonable consultation and assistance for a period of no more than ​ for the purpose of disclosing and providing to the Continuing Party, all the Unum Reversion IP or the SGI Reversion IP (as the case may be) not already in the Continuing Party’s possession that is relevant to the Reversion Product, and, at the Continuing Party’s request, all then-existing commercial arrangements to the extent relating solely and specifically to the Reversion Product that the Opt-Out Party is able, using reasonable commercial efforts, to disclose and provide to the Continuing Party, in each case, to the extent reasonably necessary or useful for the Continuing Party to commence or continue Researching, Developing, Manufacture (but only to the extent permitted pursuant to [Section 3.3(g)(iii)]) or Commercializing the Reversion Product. The foregoing will include assigning or sublicensing, upon request of the Continuing Party, any agreements with Third Party vendors to the extent they specifically cover the sale of the Reversion Product to the extent possible. If any such contract between the Opt-Out Party and a Third Party is not assignable to the Continuing Party (whether by such contract’s terms or because such contract does not relate specifically to the Reversion Product) but is otherwise reasonably necessary or useful for the Continuing Party to commence or continue Researching, Developing, Manufacture (but only to the extent permitted pursuant to [Section 3.3(g)(iii)]) or Commercializing the Reversion Product, then the Opt-Out Party will reasonably cooperate with the Continuing Party in the Continuing Party’s efforts to obtain from such Third Party the assignment or sublicense of such contract or of that portion of such contract that solely relates to Researching, Developing, Manufacture (but only to the extent permitted pursuant to [Section 3.3(g)(iii)]) or Commercializing the Reversion Product.